Off-colour … the Hate Poetry team, with Kazim, Kiyak and Musharbash, second, third and fourth from right.
Photograph: Thies Raetzke

‘When it comes to you Muslims,” Hasnain Kazim tells the audience, “we Germans are going to pick up where we left off with the Jews. It would please me if the first time we meet is when your smoke is rising out of the chimney.”

Under normal circumstances, such bile delivered from a Berlin stage would be greeted with shrieks of horror. But Kazim, a 40-year-old journalist with Spiegel Online, is treated to rollicking laughter and applause instead. This, after all, is Hate Poetry night in Berlin, an opportunity for a troupe of German journalists, all of whom have vaguely Muslim-sounding names, to read out some of the more creatively despicable messages clogging up their inboxes.

Disturbingly, each has plenty to choose from, and the fountain of hatred flows late into the evening, with insults like these: “I have nothing against Muslims as long as the only place they are staying is at the local cemetery” and “Sod off you tosser. I piss on your Muslim flag. People are losing their heads, and you worry about whether your child-fucking prophet can be banned?”

The journalists are also subjected to more common insults, like being called “stealth jihadists” and “undercover agents for the Islamisation of Europe”. Many are frequently told they should leave the country. “Just because you’re not wearing a headscarf,” read one, “doesn’t mean you’re not fanatical.” Often, as with Kazim, the son of Indian-Pakistani immigrants to Germany, the recipients aren’t even Muslim.

Rather than suffer such indignities in silence, the writers banded together to form a kind of slam-poetry series, where the most imaginative and eloquently abhorrent diatribes are read out as mesmerising, high-concept theatre. At the event I’m at, the stage is decorated with objects of oriental and German kitsch – a garish melange paying homage to the heritages of the performers. There are Turkish, Kurdish and German flags, posters of Turkish PM Recep Tayyip Erdogan, images of Kurdistan Workers’ Party leader Abdullah Öcalan, a photo of Arsenal FC’s Mesut Özil, a Charlie Hebdo cover, prayer rugs and strands of garlic. Many of the journalists are dressed up, too, with one wearing a keffiyeh and another an Indian sherwani.

The show is presented as a competition, with a hostess awarding prizes in such categories as “Dear Mr Asshole and Dear Ms Cunt” or “Subscription Cancellation”. The prizes include a yellow safety vest adorned with the words “Sharia Police” and a mosque-shaped alarm clock. The most outrageous letters are greeted with showers of confetti and an atmosphere of political incorrectness prevails, with frequent off-colour jokes about everything from Hitler to circumcision. “People often tell us we have theatrical talent,” says Mely Kiyak, a 38-year-old Kurdish-German columnist for Die Zeit Online. “The fact is that these letters are so full of rage and drama, they practically stage themselves.”

Germany is home to around 4 million Muslims, less than 6% of the population, but unease about Islam appears to be growing in the country. In a November survey by pollster Emnid, 61% of Germans said Islam doesn’t fit in the western world, while 40% said the presence of Muslims made them feel like foreigners in their own country. Although Germany lacks the kind of strong, overtly anti-Muslim political party that many of its neighbours have, such statistics indicate that Islamophobia is more mainstream than it is marginal. The widely publicised protests throughout the winter in Dresden by Pegida (which in English stands for Patriotic Europeans Against the Islamisation of the West) have underscored that point.

‘These letters are so full of rage and drama, they stage themselves’ … Hate Poetry. Photograph: Thies Raetzke

In fact, Hate Poetry travelled to Dresden for a performance in December specifically to counter the now-diminishing Pegida marches. So many Dresdeners wanted to attend that chairs had to be taken out in order to pack them in. “When 15,000 people are taking to the streets in German cities to protest against minority religions, something is seriously, seriously wrong,” says Yassin Musharbash, 39, a journalist with Die Zeit whose father is Jordanian. “This just cannot be happening.”

Kiyak describes the emails as a “desperate attempt” by their authors “to get noticed, because they have the feeling that journalists with immigrant backgrounds are spreading and are somehow trying to take away something that belongs to them”. Explaining the selection criteria for letters to be read on stage, she says it’s about “digging up the truffles among the contempt”. One, received by Mohamed Amjahid, a 27-year-old Moroccan writer with Der Tagesspiegel, reads: “You may be able to write well, but you still have to leave Germany.” Another says: “I remain convinced that Mohammedans are dangerous and a threat to democracy. That’s why I propose a referendum to make all Muslims leave.”

As Musharbash says: “We know they are terrible, but we don’t want to feel like victims or waste an evening crying over them.” Instead, Hate Poetry relies on the group therapy offered by comedy and a public airing. “We shoot the shit back into circulation,” he says. What many in the group find most disturbing is that the letters come from all segments of society, even the well-educated, and are in no way the exclusive realm of neo-Nazis or rightwing populists. “It’s easy to laugh at an obvious idiot,” says Musharbash, “but it’s not so easy when you start to realise some of these people spend a lot of time coming up with these arguments.”

Hate Poetry began when former journalist Ebru Tasdemir, 41, saw a friend post an Islamophobic hate mail on Facebook several years ago. She found several journalists with similar stories, and they agreed to experiment with a kind of cabaret-meets-revue show. The first took place in Berlin in 2011. “Basically, we did what we feel most comfortable doing, which is getting wasted and having fun,” says Musharbash. “The audience immediately liked it and we realised, by the end of the evening, we had created something magical.”

Anyone thinking such an event might work in Britain will be interested to know that Musharbash, who speaks accent-free English, has hinted that he and his colleagues might take the show to the UK. He says he finds the experience of appearing on stage a bit like visiting a hamam. “You get rid of all the shit. After that, you feel clean. There’s a cathartic element.”

It’s not always clear the audience feels the same way. The laughter is raucous, but gasps of shock can also be heard. After a Wagnerian-length show of over four hours, the performance closes with Musharbash granting absolution to the audience. “You don’t need to feel bad,” he tells them. “Tonight, it was completely fine to laugh about racism.”

• The next Hate Poetry is at Theaterlabor in Bielefeld, Germany, on 7 March.